JPS6338307Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an intermediate connecting shaft for an earth auger used when the excavation length is desired to be longer than a predetermined excavation length of the auger.

Prior Art When excavating a hole in the ground using an earth auger, the auger descends until the lower part of the hydraulic motor at the upper end contacts the resting stop provided at the lower end of the leader mast. Interrupt the excavation, add an intermediate joint shaft to the middle of the auger, and start digging. If you want to dig even deeper, you can add another intermediate joint shaft, but if you want to skip this step, you can achieve your goal by making the intermediate joint shaft extendable. However, the auger shaft is hollow in order to excavate through a cement mill or the like, and therefore, if the center joint shaft is made to be telescopic, it is necessary to devise a watertight connection structure for the hollow portion. The present invention was provided based on this technical background.

Purpose: When this device is installed in the middle of an auger, it can be used longer than the auger that has a predetermined length that matches the length of the leader mast, and can be extended and retracted in multiple stages.
Another object of the present invention is to provide an earth auger center joint shaft which has a perfect watertight connection of the hollow portion, has an expandable structure, and is robust against rotation.

Configuration: A cylinder A having a joint 1 for connecting to the auger shaft at one end is provided with a rectangular cylindrical hole 2 extending inward from the open end at the other end,
Inside a square cylinder-shaped plunger B having a joint part 3 to another auger shaft at its outer end, there is an inner cylindrical surface part 4 continuing from the joint part.
is provided, and the plunger B is inserted into the square tube hole 2.
It can be slid freely into the slot and fixed in multiple stages.
This is an intermediate joint shaft for an earth auger in which a cylindrical portion 5 continuing from the joint portion 1 toward the inner depth within the cylinder A and the inner cylindrical surface portion 4 on the plunger side are slidably fitted in a watertight manner.

Example In the example shown in FIGS. 1 and 2,
Reference numeral 1 designates a joint part for inserting into a joint part 25a (to be described later) of a hydraulic drive motor and fixing it with a pin, which has a hexagonal pillar plug shape with a hollow hole 5a, and is attached to the upper end of cylinder A (left side in the figure) by a mounting collar 12. A cylindrical portion 5 extends integrally and coaxially from the hollow hole 5a. 2 is cylinder A
is a rectangular cylindrical hole formed coaxially with the cylindrical portion 5 from the lower end (right side in the figure) toward the inside, and the inner deep part of the cylinder A beyond the rectangular cylindrical hole 2 is an expansion surrounded by an inner cylindrical surface 6. It's becoming Space 7. Reference numeral 3 denotes a socket-type joint part into which the hexagonal prism plug-shaped joint part of the auger connected below is inserted and fixed with a pin, and is fixed to the outer end of the plunger B. As shown in FIG. 3, the plunger B is slidably fitted into the square cylindrical hole 2, and has an inner cylindrical surface portion 4 coaxially extending from the hollow hole 3a of the joint portion 3 toward the tip. is provided. The tips of the inner cylindrical surface portion 4 and the plunger B are aligned, and as shown in FIG. 5, a common end plate 8 is screwed onto the tip of the plunger B and fixed to each other. The peripheral edge of this end plate 8 is in sliding contact with the inner cylindrical surface 6 of the cylinder A, and the notch 9 of the end plate provided at the opposing portion serves as a passage groove for grease and also as a passage for the drain plug 10 when the plunger moves. Become. 14 is a flange portion of the plunger B, and 15 is a constriction portion. Reference numeral 16 denotes a stopper lid of a gasket 17 provided around the plunger B, which is screwed to the base end of the cylinder A. Reference numeral 13 denotes a V-shaped packing attached to the outer periphery of the inner end of the cylindrical portion 5 so as to be in contact with the inner cylindrical surface portion 4. 18 is a grease inlet. 19 is a pin hole into which a pin P for fixing cylinder A and plunger B is inserted;
As shown in FIG. 4, both side surfaces of the square tube hole 2 and both side surfaces of the plunger B that are in contact with these are bored in the cylinder A and the plunger B at different levels. Of these pin holes, two or more groups are provided such that the half holes on the plunger B side are 19a at the base and the half holes at the tip are 19b.

In FIG. 6, reference numeral 20 denotes a neck holder that is fitted into the constricted portion 15, and has a stopper hole 21, and 22 is a connecting fitting that has a pin 23.

When using the above-described intermediate joint shaft, grease is injected from the grease inlet 18 to fill the space between the square cylinder surface 2 and the plunger B, the expansion space 7, the space between the plunger B and the inner cylinder surface 4, etc. I'll keep it. This is to prevent water from entering this part from inside and outside, and after use, the drain plug 10 is pulled out to allow water to escape.

How to use the above-mentioned center joint shaft will be explained with reference to FIGS. 7a and 7b. In the figure, C is a leader mast, which is erected by a boom D extending from the excavator main body. Parallel guide rod 2 on the front of this leader mast C
4 includes an auger drive motor 25 and a resting device 2.
The upper end joint part 1 of the intermediate joint shaft is connected with a pin to the joint part 25a of the drive motor 25, and the upper end of an auger 27 having a digging claw is attached to the lower end joint part 3 of the intermediate joint shaft. The joint is fixed with a pin. When the drive motor 25 is rotated and the hole is drilled while the main rope 28 is freed in this manner, the auger 27 is lowered and the lower end of the intermediate joint shaft reaches the upper part of the resting device 26. At this point, the drive motor 25 is stopped, and the constriction part 15 of the intermediate joint shaft is
Fit the neck holder 20 to the pin 23 of the connecting fitting 22.
is inserted into the hole 21, the neck restraint device 20 is placed on the cylindrical mouth of the resting device 26, the middle joint shaft is supported upward, the pin P is pulled out, and the drive motor 25 is raised by the main rope 28. , as shown in FIG. 7b, pull out the plunger B upward, stop it at an appropriate position, and drive the pin P into the pin holes 19 and 19b again. After this, the necking tool 20 is removed and digging is started again.

The connection of the above-mentioned intermediate joint shafts is not limited to one, but two or more may be connected.

Effects The center joint shaft according to the present invention has a square plunger B inserted into the square tube hole 2 of the cylinder A so that it can be fixed in multiple stages, so the leader mast is shortened and the auger is also shortened. It is easy to handle during transportation and installation because it can be attached with a 2-inch screw, and it is characterized by the fact that the center joint shaft can be extended to drill a deep hole if necessary. Since the cylindrical part 5 extending from the joint part 1 on the cylinder side is slidably fitted in a water-tight manner, water will not flow from inside the middle joint shaft to the sliding part of the plunger and cylinder, and the plunger B is rectangular. Since it is fitted into the rectangular tube hole 2, it also has the advantage that there is no slippage between the two parts during rotation, and that it is solid.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front sectional view of the present invention, Fig. 2 is a partially cutaway front view, Fig. 3 is a sectional view taken along line E-E, and Fig. 4 is a partially cutaway front view of the present invention.
The figure is a sectional view taken along the line FF, Figure 5 is a sectional view taken along the line GG,
FIG. 6 is an exploded perspective view of the neck holder, and FIGS. 7a and 7b are partial side views of the earth auger illustrating the sequence of usage of the above-mentioned intermediate connecting shaft. In the diagram, A...Cylinder, B...Plunger, 1
...Joint part, 2...Square tube hole, 3...Joint part, 4...
...Inner cylindrical surface part, 5...Cylindrical part.

Claims (1)

[Scope of utility model registration request] A rectangular cylindrical hole facing inward from the open part of the other end of the cylinder, which has a joint part to an auger shaft at one end, is provided at the outer end, and a square cylinder-shaped plunger having a joint part to another auger shaft is provided at the outer end. An inner cylindrical surface part continuing from the joint part is provided inside the cylinder, and the plunger is slidably inserted into the rectangular cylindrical hole on the cylinder side so that it can be fixed in multiple stages. and the inner cylindrical surface portion on the plunger side are slidably fitted in a watertight manner to each other.